Lactase non-persistent genotype distribution in Italy.

BACKGROUND: Adult-type hypolactasia is a frequent condition of lactose malabsorption; in Europe the distribution of adult-type hypolactasia have been shown to display a North-South gradient. Genotyping for LCT-13910 C>T polymorphism has been proposed as a useful diagnostic marker of adult-type hypolactasia. Data concerning lactase non-persistent genotype distribution in Italy are confused and not well characterized. The aim of this study was to determine the prevalence of CC-genotype corresponding to lactase non-persistence in Italian population.

METHODS: We genotyped 1312 adult Italian subjects for LCT-13910 C>T polymorphism by KASPar chemistry (KBioscience Ltd., Hoddesdon, England, UK).

RESULTS: The frequency of the lactase non-persistence genotype of our sample was 62.3% that was higher than the values published for adult hypolactasia in Italy. In our study a frequency of 58.6%, 74.1% and 67.1% was detected in the three main macro-regions of Italy (North, Center, and South), respectively.

CONCLUSIONS: For the first time we analyzed the distribution of the LCT-13910 CC genotype in a big population of Italian subjects. Our data did not validate the presence of a North-South gradient for adult hypolactasia along the Italian peninsula.